package com.thaiopensource.relaxng.output.dtd;

class AttributeType
{
  private AttributeType ()
  {}

  static final AttributeType EMPTY = new AttributeType ();
  static final AttributeType SINGLE = new AttributeType ();
  static final AttributeType MULTI = new AttributeType ();

  static AttributeType group (final AttributeType at1, final AttributeType at2)
  {
    if (at1 == EMPTY)
      return at2;
    if (at2 == EMPTY)
      return at1;
    return MULTI;
  }
}
